1. Field of the Invention
The present invention relates to high-frequency signal lines and electronic devices, more particularly to a high-frequency signal line including a signal line provided on a flexible element assembly, and an electronic device including the high-frequency signal line.
2. Description of the Related Art
As a high-frequency line for connecting high-frequency circuits, a coaxial cable is typically used. Coaxial cables are widely used because they can be deformed, e.g., bent, easily, and are inexpensive.
Incidentally, recent years have seen high-frequency devices, such as mobile communications terminals, becoming more compact. Accordingly, it is becoming more difficult to keep space in high-frequency devices for disposing coaxial cables having circular cross sections.
Accordingly, there is a signal line proposed by Japanese Patent Laid-Open Publication No. 2011-71403. The signal line disclosed in Japanese Patent Laid-Open Publication No. 2011-71403 includes a signal line and two ground conductors provided in a body formed by laminating a plurality of insulating sheets made of a flexible material. The signal line is provided between the two ground conductors disposed on opposite sides in the direction of lamination. That is, the signal line and the two ground conductors form a stripline structure. The thickness of such a signal line in the direction of lamination is less than the diameter of a typical coaxial cable. Therefore, the signal line can be accommodated in a small space where a typical coaxial cable cannot be placed.
However, there is difficulty in bending the signal line disclosed in Japanese Patent Laid-Open Publication No. 2011-71403 when in use. The ground conductors used in the signal line are made of copper foil resistant to deformation. Accordingly, when a strong force is applied to the ground conductors by bending the signal line, the ground conductors might be broken.